NXP LPCXpresso55S28

Overview

The LPCXpresso55S28 development board provides the ideal platform for evaluation of and development with the LPC552x/S2x MCU based on the Arm® Cortex®-M33 architecture. The board includes a high-performance onboard debug probe, audio subsystem and accelerometer, with several options for adding off-the-shelf add-on boards for networking, sensors, displays, and other interfaces.

LPCXpresso55S28

Hardware

  • LPC55S28 Arm® Cortex®-M33 microcontroller running at up to 150 MHz

  • 512 KB flash and 256 KB SRAM on-chip

  • Onboard, high-speed USB, Link2 debug probe with CMSIS-DAP and SEGGER J-Link protocol options

  • UART and SPI port bridging from LPC55S28 target to USB via the onboard debug probe

  • Hardware support for external debug probe

  • 3 x user LEDs, plus Reset, ISP (3) and user buttons

  • Micro SD card slot (4-bit SDIO)

  • NXP MMA8652FCR1 accelerometer

  • Stereo audio codec with line in/out

  • High and full speed USB ports with micro A/B connector for host or device functionality

  • MikroEletronika Click expansion option

  • LPCXpresso-V3 expansion option compatible with Arduino UNO

  • PMod compatible expansion / host connector

For more information about the LPC55S28 SoC and LPCXPresso55S28 board, see:

Supported Features

The lpcxpresso55s28 board configuration supports the hardware features listed below. For additional features not yet supported, please also refer to the NXP LPCXPRESSO55S69 , which is the superset board in NXP’s LPC55xx series. NXP prioritizes enabling the superset board with NXP’s Full Platform Support for Zephyr. Therefore, the lpcxpresso55s69 board may have additional features already supported, which can also be re-used on this lpcxpresso55s28 board:

Interface

Controller

Driver/Component

NVIC

on-chip

nested vector interrupt controller

SYSTICK

on-chip

systick

IOCON

on-chip

pinmux

GPIO

on-chip

gpio

I2C

on-chip

i2c

SPI

on-chip

spi

USART

on-chip

serial port-polling; serial port-interrupt

WWDT

on-chip

windowed watchdog timer

ADC

on-chip

adc

CLOCK

on-chip

clock_control

RNG

on-chip

entropy; random

IAP

on-chip

flash programming

Other hardware features are not currently enabled.

The default configuration file boards/arm/lpcxpresso55s28/lpcxpresso55s28_defconfig

Connections and IOs

The LPC55S28 SoC has IOCON registers, which can be used to configure the functionality of a pin.

Name

Function

Usage

PIO0_26

SPI

SPI MOSI

PIO0_29

USART

USART RX

PIO0_30

USART

USART TX

PIO1_1

SPI

SPI SSEL

PIO1_2

SPI

SPI SCK

PIO1_3

SPI

SPI MISO

PIO1_4

GPIO

RED LED

PIO1_6

GPIO

BLUE_LED

PIO1_7

GPIO

GREEN LED

PIO1_20

I2C

I2C SCL

PIO1_21

I2C

I2C SDA

System Clock

The LPC55S28 SoC is configured to use PLL1 clocked from the external 24MHz crystal, running at 144MHz as a source for the system clock. When the flash controller is enabled, the core clock will be reduced to 96MHz. The application may reconfigure clocks after initialization, provided that the core clock is always set to 96MHz when flash programming operations are performed.

Serial Port

The LPC55S28 SoC has 8 FLEXCOMM interfaces for serial communication. One is configured as USART for the console and the remaining are not used.

Programming and Debugging

Build and flash applications as usual (see Building an Application and Run an Application for more details).

Configuring a Debug Probe

A debug probe is used for both flashing and debugging the board. This board is configured by default to use the LPC-Link2 CMSIS-DAP Onboard Debug Probe.

Configuring a Console

Connect a USB cable from your PC to P6, and use the serial terminal of your choice (minicom, putty, etc.) with the following settings:

  • Speed: 115200

  • Data: 8 bits

  • Parity: None

  • Stop bits: 1

Flashing

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b lpcxpresso55s28 samples/hello_world
west flash

Open a serial terminal, reset the board (press the RESET button), and you should see the following message in the terminal:

***** Booting Zephyr OS v2.4.0 *****
Hello World! lpcxpresso55s28

Debugging

Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b lpcxpresso55s28 samples/hello_world
west debug

Open a serial terminal, step through the application in your debugger, and you should see the following message in the terminal:

***** Booting Zephyr OS zephyr-v2.4.0 *****
Hello World! lpcxpresso55s28